By means of a 5-week vitamin B-complex .supplementation, associations between indices of vitamin B1, B2, and B6, status (activation coefficients [AC] for erythrocyte transketolase, glutathione reductase, and aspartate aminotransferase) and exercise-induced blood lactate concentration were studied. Subjects, 42 physically active college students (18–32 yrs), were randomized into vitamin (n=22) and placebo (n=20) groups. Before the supplementation there were no differences in ACs or basal enzyme activities between the groups. The ACs were relatively high, suggesting marginal vitamin status. In the vitamin group, all three ACs were lower (p<0.0001) after supplementation: transketolase decreased from l. 16 (1.14–1.18) (mean and 95% confidence interval) to 1.08 (1.06–1.10); glutathione reductase decreased from 1.33 (1.28–1.39) to 1 .I4 (1.1 1–1.17); and aspartate aminotransferase decreased from 2.04 (1.94–2.14) to 1.73 (1.67–1.80). No changes were found after placebo. Despite improved indices of vitamin status, supplementation did not affect exercise-induced blood lactate concentration. Hence no association was found between ACs and blood lactate. It seems that marginally high ACs do not necessarily predict altered lactate metabolism.

Leslie N. Silk, David A. Greene and Michael K. Baker

Research examining the preventative effects of calcium and vitamin D supplementation has focused on children and females, leaving the effects on male bone mineral density (BMD) largely unexplored. Thus, the aim of this systematic review and meta-analysis is to examine the efficacy of calcium supplementation, with or without vitamin D for improving BMD in healthy males. Medline, EMBASE, SPORTDiscus, Academic Search Complete, CINHAHL Plus and PubMed databases were searched for studies including healthy males which provided participants calcium supplementation with or without vitamin D and used changes to BMD as the primary outcome measure. Between trial standardized mean differences of percentage change from baseline in BMD of femoral neck, lumbar spine, total body and total hip sites were calculated. Nine studies were included in the systematic review with six references totaling 867 participants contributing to the meta-analysis. Significant pooled effects size (ES) for comparison between supplementation and control groups were found at all sites included in the meta-analysis. The largest effect was found in total body (ES = 0.644; 95% CI = 0.406–0.883; p < .001), followed by total hip (ES = 0.483, 95% CI= 0.255–0.711, p < .001), femoral neck (ES = 0.402, 95% CI = 0.233–0.570, p = .000) and lumbar spine (ES = 0.306, 95% CI = 0.173–0.440, p < .001). Limited evidence appears to support the use of calcium and vitamin D supplementation for improving BMD in older males. There is a need for high quality randomized controlled trials, especially in younger and middle-aged male cohorts and athletic populations to determine whether supplementation provides a preventative benefit.

Paula J. Ziegler, Judy A. Nelson and Satya S. Jonnalagadda

The present study examined the prevalence of dietary supplement use among elite figure skaters, gender differences in supplement use, and differences in nutrient intake of supplement users versus non-users. Male (n = 46) and female (n = 59) figure skaters completed a supplement survey and 3-day food records. Descriptive analysis, chi-square test, and independent t tests were used to analyze the data. Sixty-five percent of male (n = 30) and 76% of female (n = 45) figure skaters reported use of supplements. Forty-seven percent of males and 55% of females reported daily use of supplements. Multivitamin-mineral supplements were the most popular dietary supplements consumed by figure skaters. Significant gender differences were observed in the use of multivitamin-mineral supplements (61% males vs. 83% females, p < .05). Echinacea and ginseng were popular herbal supplements used by these skaters. The 3 main reasons given by male figure skaters for taking supplements were: to provide more energy (41%), to prevent illness or disease (34%), and to enhance performance (21%). Among female figure skaters, the 3 main reasons given were: to prevent illness or disease (61%), to provide more energy (39%), and to make up for an inadequate diet (28%). Significant differences (p < .05) were observed in protein, total fat, saturated fat, polyunsaturated fat intakes, and % energy from carbohydrate and total fat of male supplement users versus non-users, with supplement users having higher intakes except for percent energy from carbohydrate. Sodium was the only nutrient significantly different (p < .05) among female supplement users versus non-users, with supplement users having lower intakes. Given the popularity of dietary supplements, it is important to understand the factors influencing athletes’ use of supplements, their knowledge and attitudes regarding supplements, dosage of supplements used, and the effectiveness of these dietary supplements in meeting the goals of the athletes.

This study examined the traditional (single and multivitamin/mineral supplements) and nontraditional supplement (herbals, botanicals, and other biologic and nutrient supplements) use by female athletes. Frequency, reasons for use, and sources of supplement information were assessed with a self-report questionnaire. Participants were 162 collegiate female varsity athletes. More than half of all athletes used some type of supplement at least once a month (65.4%). Thirty-six percent (n = 58) of the sample used a multivitamin and mineral with iron. Twelve percent (n = 19) reported amino acid/protein supplement use and 17% (n = 29) used an herbal/botanical supplement. The most frequently cited reason for supplement use was “good health” (60.1%). A major source of information on supplements reported was family (53%). With the general rise in supplement use, nutrition education on the use of traditional and non-traditional supplements is warranted.

The authors’ aim was to examine the prevalence of (daily) dietary-supplement (DS) use among elite adolescent athletes and to differentiate use by different types of DS according to their function. Data were analyzed for associations between users of these DS types, sociodemographic, sport-specific characteristics, and opinion on the need for DS. In addition, sources of supply and information were examined. In the framework of the GOAL Study, 1,138 German elite adolescent athletes (14–18 yr) answered questions about DS. The data were analyzed to identify groups at risk for using DS after a classification by supplemental function. Of the young athletes, 91.1% reported DS use during the previous month. (Daily) DS use was significantly associated with sex, kind of sport, and the weekly duration of sporting activity. Furthermore, some athletes were required to use DS by their sporting organization. DS use was more likely in these athletes than in those whose sporting organizations had no such requirement. Overall, DS with short- and long-term supplemental function were mostly associated with the use of magnesium. However, DS with medium-term muscle-building function played an important role among daily users. The main source of information about DS was coaches; main source of supply was parents. Professional education is urgently needed, as 9 out of 10 athletes used DS, and strong positive opinions toward the use of DS were present, particularly in the DS users.

Martin Kristiansen, Ryna Levy-Milne, Susan Barr and Anne Flint

The purpose of this study was to assess reasons for and prevalence of supplement use among varsity athletes and nonvarsity athlete students (controls) at a Canadian university. A questionnaire, distributed to 247 varsity athletes and 204 controls, included variables regarding sports participation, supplements used, reasons for usage, perceived effects, and areas of interest about supplements. Response rates were 85.5% among varsity athletes and 44.6% among controls. Supplements were used by 98.6% of varsity athletes and 94.3% of controls. Varsity men most often reported using sports drinks, and used these (and carbohydrate gels, protein powder, and creatine) more than varsity women. Caffeine products were most often reported by other groups. Health professionals and the Internet were the most reported information sources, while friends most often recommended supplements. Many subjects indicated knowing little about supplements and wanting to learn more. Results indicate a need for nutrition education among both varsity athletes and university students.